Embodiments of the invention are directed, in general, to Power Line Communication (PLC) systems and, more specifically, OFDM transmissions in PLC channels.
Various OFDM-based standards exist for narrowband power-line communications, such as the G3-CENA, G.hnem, IEEE-P1901.2 standards. In each of these standards, the OFDM system is designed assuming a fixed cyclic prefix length.
In some PLC communication links, it is envisioned that the channel delay spread may be significantly different from the cyclic prefix length specified for the standard in use. If the channel delay spread is longer than the cyclic prefix, this will result in an signal-to-noise ratio (SNR) loss in the received data. If the channel delay spread is shorter than the cyclic prefix, this will result in a reduction in channel throughput which may be significant for long packet length transmissions.
Power line communications (PLC) include systems for communicating data over the same medium that is also used to transmit electric power to residences, buildings, and other premises, such as wires, power lines, or other conductors. In its simplest terms, PLC modulates communication signals over existing power lines. This enables devices to be networked without introducing any new wires or cables. This capability is extremely attractive across a diverse range of applications that can leverage greater intelligence and efficiency through networking. PLC applications include utility meters, home area networks, lighting, and solar.
PLC may also serve as an important enabling technology for the mass deployment of solar equipment by providing a communication channel to solar inverters for monitoring and managing power across the grid by utility companies. While radio frequency (RF) communications have made some progress in solar installations, PLC offers an ideal means for connecting equipment with high reliability and at a low cost on DC or AC lines.
PLC is a generic term for any technology that uses power lines as a communications channel. Various PLC standardization efforts are currently in work around the world. The different standards focus on different performance factors and issues relating to particular applications and operating environments. Two of the most well-known PLC standards are G3 and PRIME. G3 has been approved by the International Telecommunication Union (ITU). IEEE is developing the IEEE P1901.2 standard that is based on G3. Each PLC standard has its own unique characteristics. PRIME is designed for low voltage lines with low noise and targets higher data rates. On the other hand, G3 is designed for medium voltage lines and targets lower data rates.